Not only did Browning find him a surgeon, she provided him with a physical therapist whom she employs at her Madison Avenue studio.

“Moneyed people in business, finance and fashion follow her around like a cult,” says Demsey, 57, who found Browning two and a half years ago through former CNN fashion correspondent Alina Cho. “She’s ‘Sex and the City’ meets ‘The Terminator.’ ”

Demsey works out with Browning three to four times a week, exercising one to two muscle groups per session to complete exhaustion, as well as doing at least 20 minutes of cardio and special leg exercises to help speed his knee recovery.

“I am in an image business, and you should look like the beneficiary of your products,” he adds. “I have to uphold a certain standard and not be a schlub. Mary Ann helps me eradicate my inner schlub.”

Mary Ann Browning trains Estee Lauder honcho John Demsey — and even calls his assistants to make sure he is eating well.Stefano Giovannini

While Browning is the go-to fitness guru for beauty industry bigwigs, Ngo Okafor is the trainer du jour for some of the city’s most glamorous fashionistas.

The halls of Hearst and Time Inc. have been buzzing about Okafor, who spent six years modeling for Wilhelmina and now charges $175 and up for a personalized hourlong session at the gym.

“I give people style, fitness and beauty tips, so I want to make sure I’m a reflection of that advice,’’ explains InStyle beauty director Kahlana Barfield, 32, who meets with Okafor three times a week in preparation for her October wedding.

And at a recent session at Peak Performance in the Flatiron District, he was relentless.

“You can’t be on Instagram!” barks the 40-year-old trainer, who stands 6-foot-3 and weighs 200 pounds. “You have 10 months to get into that dress!’’

Browning and Okafor are two of the most talked-about fitness gurus of the moment with a unique specialty — training people in the beauty and style industries.

But getting into gorgeous shape can be an ugly business.

“She harasses my assistants,” Demsey says of Browning. “At first they asked, ‘Who the hell is this woman who keeps calling and telling us what to order you for lunch?’ ”

Browning, a native of South Africa who arrived in NYC in 1999 almost penniless after a financially debilitating divorce, goes well beyond pushing clients to do that extra crunch.

The petite blond trainer, who opened her studio in 2005, is known for infiltrating all aspects of her clients’ lives to make sure they stay in tiptop shape.

The Browning method — which can go so far as to include her shopping for clients’ workout clothes or vetting a menu ahead of their dinner plans — doesn’t come cheap either.

She charges between $300 and $400 per one-hour session, depending upon the time slot. (Sessions with her team cost less.)

But that’s practically a business expense for some fashion and beauty mavens.

Frederic Fekkai (left) and Samantha Boardman both sweat it out with fitness trainer Mary Ann Browning. John Lamparski/WireImage; Nicholas Hunt/PatrickMcMullan.com

Hair guru Frederic Fekkai, who sold his company to Procter & Gamble but remains an active consultant, thrives on Browning’s no-nonsense philosophy.

“It’s always interesting for Type-A people like us who feel they need to direct everyone to take direction from someone else,’’ the 56-year-old Fekkai says. “But I love when a pro gives me strict rules or orders or prescriptions: I don’t respond to wishy-washy people.’’

Browning not only trained Fekkai at her studio, she took him to Central Park to work out on his bike.

“I couldn’t keep up with her,’’ he sighs. “She gives me a hard time when I am lagging behind, but that’s what I pay her for.’’

She gives me a hard time when I am lagging behind, but that’s what I pay her for … I don’t respond to wishy-washy people.

- Frederic Fekkai on personal trainer Mary Ann Browning

Socialite, Cornell-trained psychiatrist and mother of two Samantha Boardman, who maintains her killer bod with Browning’s help, recalls the time Browning sent her photographs of Elle Macpherson to keep her motivated while she was on vacation.

The attached note warned Boardman not to indulge in any croissants.

“Mary Ann does scold, but she has ways of motivating that get people to do things they would never do,’’ says Boardman. “She would throw your phone out the window if you tried to get on it. She is relentless, and she is with you all day long, love it or hate it.”

Barfield, meanwhile, dropped seven pounds the first month of working with Okafor and is already planning a fitted wedding gown.

“It will be tight, and there will be skin exposed,’’ the Fort Greene resident says. “I’ve worked out too hard not to show it off!”

After being bullied in high school, Okafor trained as a boxer and won two consecutive Golden Glove competitions before starring in ads for Gatorade and posing with supermodel Gisele Bündchen. He parlayed his fitness prowess into personal training, an enterprise that has allowed him the freedom to create his own schedule and go on auditions.

“I really care about my clients and it’s all about them, not me,’’ he says. “I walk the walk and work out along with them, which really motivates them.’’

“Ngo pushes me to places I didn’t know were humanly possible,’’ says Chopin Rabin, the 35-year-old executive director of Global Communications for NARS cosmetics who lives in Murray Hill and has lost 30 pounds on a strict regimen with Okafor that includes boxing, strength training and cardio intervals.

“You can say, ‘I hurt my arm,’ and he says, ‘Too bad, you have another arm.’ ”

But if that’s the cost of looking good when Fashion Week rolls around, so be it.

“I feel like I am fighting for my clients,’’ says Okafor. “I stay on top of them and follow up because I want them to win — especially the girls in fashion and beauty.

“I know how cutthroat that industry is. It’s war: There are girls waiting for them to slip up so they can take their jobs. They have to stay on top, and it all starts with the way they look.’’

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Brian Flynn

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Andia Winslow

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The Yale alum and master-certified fitness pro developed a track and field-inspired workout that has helped condition clients in entertainment, media and sports, including Brooke Shields and Denver Bronco Tony Carter.

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